纖維素水解酵素是一群水解酵素(hydrolytic enzyme)的總稱，經由彼此間的協同作用(synergism)，將不溶性水的纖維素最終分解成可溶性的葡萄糖。利用纖維素水解酵素分解自然界中最豐富的纖維素成單糖(五碳糖及六碳糖)也將是生質能源的第一步。由於酵素價格高，故增加其使用時數及次數尤其重要，固定化為延長酵素使用次數及其多次使用後之活性。 本實驗將探討纖維素水解酵素固定在經過表面改質之幾丁聚醣擔體上最佳催化條件；幾丁聚醣的選用在於它是良好的生物高分子，一種多功能且對環境友善的現代材料，與生物體細胞有良好的生物相容性，亦可扮演保護劑角色。然而為使擔體方便回收，便以自行製備之磁性奈米粒子(Fe3O4)的添加作為考量，經實驗結果得知，控制濃度(0~20mg/ml)為2.5mg/ml時對於回收行為及酵素活性(R.A 14.59μmole/mg*min)考量下為較佳條件；在實驗中添加介面活性劑(surfactant)Tween 80，在隨著添加介面活性劑Tween 80濃度(0%~0.5%)時，酵素的相對活性(R.A) 也從15.881(μmole/mg*min ) 上升至21.414(μmole/mg*min)，對於固定化的效率也有所提升。而纖維素水解酵素在經過固定化之後，其對酸鹼及溫度的容忍穩定度也隨之提升，使得酵素更可以在較高溫下及較中性環境下進行操作。 Immobilization of cellulase onto chitosan by glutaradehyde has been studied. Chitosan is a polyaminosaccharide and is also attractive biomaterial has some properties that biocompatible,biodegradable and biorenewable.In this study , chitosan beads were prepared by a sprinkle-nozzle with nitrogen gas as stirring. Addition of magnetic particles make recovery convenient.Addition of surfactant Tween 80 make affinity of enzyme and substrate stronger and activity from 15.881 (μmole/mg*min ) to 21.414(μmole/mg*min). Cellulase was immobilized to the support by a covalent method.The immobilized cellulase had a higher Km than free cellulase and had better stability with respect to pH,thermal stability , reuses than free cellulase.
